Button-type secondary battery and method for manufacturing the same

Abstract

A button-type secondary battery includes: a lower can configured to operate as a first electrode terminal; an upper can coupled to the lower can to surround the lower can and configured to operate as a second electrode terminal; and a gasket between the lower can and the upper can. A recessed lower insertion groove and a recessed upper insertion groove are defined in a surface of the lower can and a surface of the upper can, which are in close contact with the gasket, respectively. The lower insertion groove and the upper insertion groove are spaced apart from each other so as not to face each other.

1 . A button-type secondary battery comprising:
 a lower can configured to operate as a first electrode terminal;   an upper can coupled to the lower can to surround the lower can and configured to operate as a second electrode terminal; and   a gasket between the lower can and the upper can,   wherein a recessed lower insertion groove and a recessed upper insertion groove are defined in a surface of the lower can and a surface of the upper can, which are in close contact with the gasket, respectively, and   wherein the lower insertion groove and the upper insertion groove are spaced apart from each other so as not to face each other.   
     
     
         2 . The button-type secondary battery of  claim 1 , wherein a portion of the gasket is introduced into the lower insertion groove and the upper insertion groove by clamping of the lower can and the upper can to form a lower insertion protrusion and an upper insertion protrusion on a surface of the gasket,
 a contact area between the lower can and the gasket increases by the lower insertion protrusion, and   a contact area between the upper can and the gasket increases by the upper insertion protrusion.   
     
     
         3 . The button-type secondary battery of  claim 1 , wherein one of the lower insertion groove and the upper insertion groove has a cross-section having a triangular shape that gradually decreases in width toward the bottom. 
     
     
         4 . The button-type secondary battery of  claim 1 , wherein the lower insertion groove or the upper insertion groove is provided in two or more, and
 the two or more lower insertion grooves or the two or more upper insertion grooves are provided to be connected to each other in a direction in which the lower can and the upper can are clamped.   
     
     
         5 . The button-type secondary battery of  claim 4 , wherein the two or more lower insertion grooves or the two or more upper insertion grooves are provided to increase in size in the direction in which the lower can and the upper can are clamped. 
     
     
         6 . The button-type secondary battery of  claim 1 , wherein the gasket comprises an outer part provided between the lower can and the upper can, an inner part supported on an inner wall of the lower can, and a connection part configured to connect an upper end of the outer part to an upper end of the inner part. 
     
     
         7 . The button-type secondary battery of  claim 1 , wherein a pressing protrusion configured to press the gasket provided between the lower can and the upper can is disposed on the lower can. 
     
     
         8 . A method for manufacturing a button-type secondary battery, the method comprising:
 preparing a lower can having a recessed lower insertion groove, an upper can having a recessed upper insertion groove, and a gasket disposed between the lower can and the upper can;   accommodating an electrode assembly, in which a first electrode, a separator, and a second electrode are alternately stacked, in the lower can;   disposing the gasket on an upper portion of the lower can, wherein the gasket comprises an outer part supported on an outer circumferential surface of the lower can, an inner part supported on an inner circumferential surface of the lower can, and a connection part connecting the outer part to the inner part; and   clamping the upper can with the lower can by disposing the upper can on an upper portion of the lower can, thereby manufacturing the button-type secondary battery,   wherein, in the preparation process, the lower insertion groove formed in the lower can and the upper insertion groove formed in the upper can are disposed to be spaced apart from each other so as not to face each other when the lower can and the upper can are coupled to each other.   
     
     
         9 . The method of  claim 8 , wherein, in the clamping, when the lower can and the upper can are clamped, a portion of the gasket is introduced into the lower insertion groove and the upper insertion groove form a lower insertion protrusion and an upper insertion protrusion on a surface of the gasket,
 a contact area between the lower can and the gasket increases by the lower insertion protrusion, and   a contact area between the upper can and the gasket increases by the upper insertion protrusion.   
     
     
         10 . The method of  claim 8 , wherein one of the lower insertion groove and the insertion groove of the upper can has a cross-section having triangular shape that gradually decreases in width toward the bottom. 
     
     
         11 . The method of  claim 8 , wherein, in the preparing, the lower insertion groove or the upper insertion groove is provided in two or more, and
 the two or more lower insertion grooves or the two or more upper insertion grooves are connected to each other in a direction in which the lower can and the upper can are clamped.   
     
     
         12 . The method of  claim 8 , wherein, in the preparing, a pressing protrusion pressing the gasket is formed on the lower can below the lower insertion groove, and
 in the clamping process, when the lower can and the upper can are clamped, since a lower portion of the gasket is fixed by the pressing protrusion, the gasket is introduced into the lower insertion groove and the upper insertion groove while being expanded in a direction of the upper can and the lower can.